Advection-Diffusion Model for Diffusion Channel Storage

The connectivity of marine populations via larval dispersal is crucial for the maintenance of fisheries production and biodiversity. Because larval dispersion takes place on different spatial scales, global operational satellite data can be successfully used to investigate the connectivity of marine populations on different spatial and temporal scales. In fact, satellite data have long been used for the study of the large and mesoscale biological processes associated with ocean dynamics. This paper presents simulations of spiny lobster larvae transport in the Tropical Atlantic using the geostrophic currents, generated by altimetry that feeds an advection/diffusion model. Simulations were conducted over the Tropical Atlantic (20ºN to 15ºS), considering four larvae release areas: the Cape Verde Archipelago, the Ivory Coast, Ascension Island and Fernando de Noronha Archipelago. We used mean geostrophic current (MGC) calculated from 2001 to 2005 to represent the mean circulation of the Tropical Atlantic. We also ran the model for the El Niño geostrophic current regime (ENGC) using part of the MGC data, representing the El Niño 2002/2003 event. Results suggest that the intensification of the mesoscale ocean processes associated with El Niño events promotes the connectivity between populations, increasing the chances of a genetic flux among different stocks. We concluded that the altimetry geostrophic current data together with a relatively simple advection/diffusion model can provide useful information about the physical dynamics necessary to conduct studies on larval dispersion.

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An efficient meshless method based on the Moving Kriging interpolation for two-dimensional variable-order time-fractional mobile/immobile advection-diffusion model

Authorea ◽

10.22541/au.158540735.59094315 ◽

2020 ◽

Author(s):

Esmail Hesameddini ◽

Ali Habibirad ◽

Mohammad Hossein Heydari ◽

Reza Roohi

Keyword(s):

Diffusion Model ◽

Meshless Method ◽

Kriging Interpolation ◽

Variable Order ◽

Two Dimensional ◽

Moving Kriging Interpolation ◽

Advection Diffusion ◽

Dimensional Variable

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Ciliary chemosensitivity is enhanced by cilium geometry and motility

10.1101/2021.01.13.425992 ◽

2021 ◽

Author(s):

David Hickey ◽

Andrej Vilfan ◽

Ramin Golestanian

Keyword(s):

Shear Flow ◽

Surface Area ◽

Diffusion Model ◽

Capture Rate ◽

Advection Diffusion ◽

Beating Frequency ◽

Sensory Functions ◽

Capture Rates ◽

Quiescent Fluid

Cilia are hairlike organelles involved in both sensory functions and motility. We discuss the question of whether the location of chemical receptors on cilia provides an advantage in terms of sensitivity. Using a simple advection-diffusion model, we compute the capture rates of diffusive molecules on a cilium. Because of its geometry, a non-motile cilium in a quiescent fluid has a capture rate equivalent to a circular absorbing region with ~ 4× its surface area. When the cilium is exposed to an external shear flow, the equivalent surface area increases to ~ 10×. Alternatively, if the cilium beats in a non-reciprocal way, its capture rate increases with the beating frequency to the power of 1/3. Altogether, our results show that the protruding geometry of a cilium could be one of the reasons why so many receptors are located on cilia. They also point to the advantage of combining motility with chemical reception.

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